Merge branch 'get_active_users_command' into '1.4.x'

Add django command to get users active on the site

See merge request !247

beat/web/utils/management/commands/list_active_users.py

+#!/usr/bin/env python
+# vim: set fileencoding=utf-8 :
+# encoding: utf-8
+
+###############################################################################
+#                                                                             #
+# Copyright (c) 2018 Idiap Research Institute, http://www.idiap.ch/           #
+# Contact: beat.support@idiap.ch                                              #
+#                                                                             #
+# This file is part of the beat.web module of the BEAT platform.              #
+#                                                                             #
+# Commercial License Usage                                                    #
+# Licensees holding valid commercial BEAT licenses may use this file in       #
+# accordance with the terms contained in a written agreement between you      #
+# and Idiap. For further information contact tto@idiap.ch                     #
+#                                                                             #
+# Alternatively, this file may be used under the terms of the GNU Affero      #
+# Public License version 3 as published by the Free Software and appearing    #
+# in the file LICENSE.AGPL included in the packaging of this file.            #
+# The BEAT platform is distributed in the hope that it will be useful, but    #
+# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY  #
+# or FITNESS FOR A PARTICULAR PURPOSE.                                        #
+#                                                                             #
+# You should have received a copy of the GNU Affero Public License along      #
+# with the BEAT platform. If not, see http://www.gnu.org/licenses/.           #
+#                                                                             #
+###############################################################################
+
+
+from django.core.management.base import BaseCommand, CommandError
+from django.contrib.auth.models import User
+from django.contrib.sessions.models import Session
+from django.utils import timezone
+
+
+def get_current_users():
+    """
+    Get the list of users active on the site.
+
+    Works better if the configuration of the site has:
+
+        SESSION_EXPIRE_AT_BROWSER_CLOSE = True
+
+    Inspired from:
+    https://www.codingforentrepreneurs.com/blog/django-tutorial-get-list-of-current-users/
+    """
+
+    active_sessions = Session.objects.filter(expire_date__gte=timezone.now())
+    user_id_list = []
+    for session in active_sessions:
+        data = session.get_decoded()
+        user_id_list.append(data.get('_auth_user_id', None))
+    # Query all logged in users based on id list
+    return User.objects.filter(id__in=user_id_list)
+
+
+class Command(BaseCommand):
+
+    help = 'Get active users'
+
+    def add_arguments(self, parser):
+        parser.add_argument('--email', '-e', action='store_true',
+                        dest='show_email', default=False, help='Set this flag'\
+                        'to also print email addresse')
+        parser.add_argument('--only-email', '-o', action='store_true',
+                        dest='show_only_email', default=False, help='Set this'\
+                        'flag to only print email addresse')
+
+    def handle(self, *args, **options):
+        current_users = get_current_users()
+        for user in current_users:
+            if options['show_only_email']:
+                print(user.email)
+            else:
+                user_data = "{} {}".format(user.first_name, user.last_name)
+                if options['show_email']:
+                    user_data += " {}".format(user.email)
+                print(user_data)
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